Speaker
Dr
Alvaro Chavarria
(University of Chicago)
Description
I will present the techniques we have developed to measure trace contamination of uranium, thorium, lead-210 and silicon-32 in the CCDs for the DAMIC experiment. I will introduce the devices, which consist of a square array of 16 million, 15 um x 15 um pixels, and a substrate thickness of 675 um. I will discuss the identification and spectroscopy (down to 100 eV) of alpha and beta particles based on the ionization patterns they produce in the substrate of the device. I will describe the algorithms that we have developed to reconstruct the end-points of electron tracks observed in a CCD. Furthermore, I will demonstrate how the high spatial resolution of the CCD allows us to reliably identify radioactive decay sequences with characteristic times between decays of up to weeks. Finally, I will describe how the CCD can also perform with high efficiency spectroscopy of alpha particles and X-rays impinging on its surface, and how this may be exploited for radioactive screening of other materials and surfaces.
Primary author
Dr
Alvaro Chavarria
(University of Chicago)
